Table 2.
Chemical identification of the faint-yellow crystal from spectra of 1H NMR/13C NMR
| Compound |
δ |
|
| 13C NMRa | 1H NMRb | |
| Faint-yellow crystal (98.46%) | 145.85 | |
| 145.63 | ||
| 113.97 | 6.79 (d; J=8.0 Hz; 2H) | |
| 121.66 | 6.95 (dd; J=2.0 Hz, 8.0 Hz; 2H) | |
| 126.68 | ||
| 114.43 | 7.05 (d; J=1.5 Hz; 2H) | |
| 148.27 | 7.55 (d; J=16.0 Hz; 2H) | |
| 115.35 | 6.23 (d; J=16.0 Hz; 2H) | |
| 169.86 | ||
| Standard caffeic acid (>99.0%) | 145.90 | |
| 145.56 | ||
| 113.84 | 6.95 (dd; J=2.0 Hz, 8.0 Hz; 2H) | |
| 121.77 | 6.79 (d; J=8.0 Hz; 2H) | |
| 126.55 | ||
| 114.25 | 7.06 (d; J=2.0 Hz; 2H) | |
| 148.24 | 7.55 (d; J=15.5 Hz; 2H) | |
| 115.26 | 6.24 (d; J=16.0 Hz; 2H) | |
| 169.90 | ||
In CD3OD
a
Measured at 125 MHz
b
Measured at 500 MHz